Wood-type golf club head

Abstract

An wood-type golf club head having plural cavities formed in a back surface of a head body. A back surface 1A of a metallic head body 1 is formed with plural cavities 5, opposite to a face 4 of the head body 1. The cavities 5 are formed by forging, thus generating even and fine metallic tissues and grain flow. Accordingly, the toughness and durability of the material can be enhanced, so that face 4 can be made thinner to a 1.0 to 3.5 mm thickness for realizing an optional weight distribution. As a result, a larger sweet area can be realized without damaging a strength of head.

What is claimed: 
     
       1. A wood-type golf club head formed by integrally joining a plurality of metallic shells including a face shell, having a face at a front side and a shaft mounting portion at one side, comprising: a plurality of cavities formed in a back surface of said face shell, each of said cavities being formed by forging, having a uniform semispherical concave portion which has a circular-shaped plan view, each having a depth relatively less than its width to form a relatively shallow cavity structure,   wherein said plural cavities comprise multi-stage ranks which are each offset by half a pitch respectively.   
     
     
       2. A wood-type golf club head according to claim 1, wherein a thickness of said face is within a range from 1.0 to 3.5 mm. 
     
     
       3. A wood-type golf club head according to claim 1, wherein each width of said cavities is within a range from 3.0 to 8.0 mm, while each depth thereof is 0.2 to 1.7 mm. 
     
     
       4. A wood-type golf club head according to claim 1, wherein a center to center distance between the adjacent cavities is within a range from 3 to 10 mm. 
     
     
       5. A wood-type golf club head according to claim 1, wherein a percentage area of said cavities to a flat portion of a back surface of said face is 70% or above. 
     
     
       6. A wood-type golf club head according to claim 1, further comprising a plurality of relatively small cavities provided along a peripheral edge of the back of the face member.